Even when Zynga was a private company, it was dogged by concerns that it was overly dependent on Facebook. After it went public, those worries were realized after Facebook altered its algorithms in a way that punished Zynga's viral promotion techniques on the social network. Starting in May, usage cratered.

So what happens when Zynga alters its agreement with Facebook to make it less dependent on the social network? The stock goes down.

So Zynga gets punished for being overly dependent on Facebook. And then it gets punished for trying to ease off its dependence.

One way to read this: Investors are not confident in Zynga's plan to grow off of Facebook—on mobile and on Zynga.com.

That's reasonable. All of Zynga's top mobile hits so far have come through acquisitions. And its Zynga.com website is still nascent. Quantcastshows a steady decline from 5 million U.S. visitors in June to 3.6 million in November. That's going in the wrong direction.

FarmVille 2 and CityVille 2, its recently released sequels, are huge hits with tens of millions of players. But those are traditional Facebook games. Zynga won't get a free hand to pursue a Facebook-independent strategy until March, which is when the companies agreed they'd start to unwind some of their exclusivity terms.

The only thing Pincus & Co. can do now is deliver real numbers. Unlike the players of its games, there's no way to buy magic points to skip a level. It's just a matter of grinding through one challenge after another.